This study investigates a retailer's incentive for sharing private demand information with a supplier who may encroach the retail channel by imposing a fixed entry cost. Although conventional wisdom ...suggests that a retailer should withhold her private demand observations to maintain an information advantage over the supplier, we obtain a different conclusion by demonstrating that the retailer may prefer to voluntarily share the demand information in anticipation of supplier encroachment. The intuition is that in face of the threat of supplier encroachment, sharing low demand information may prevent the supplier from establishing a direct selling channel, which will reduce downstream channel competition. This strategic effect of information sharing is new and only becomes dominant when there is an intermediate entry cost for encroachment and a high channel substitution rate. In contrast, when there are deviations from these conditions, the supplier's equilibrium encroachment decision is consistent and irrespective of the retailer's decision to share information, which makes withholding the demand information more beneficial to the retailer. The change of information sharing structure in the channel also leads to some unintended payoff implications, as the supplier's and channel's payoffs exhibit non‐monotonic relations to the entry cost or channel substitution rate.
Multifunctional epidermal sensor systems (ESS) are manufactured with a highly cost and time effective, benchtop, and large‐area “cut‐and‐paste” method. The ESS made out of thin and stretchable metal ...and conductive polymer ribbons can be noninvasively laminated onto the skin surface to sense electrophysiological signals, skin temperature, skin hydration, and respiratory rate.
Science teachers usually view students' uncertainty as a barrier to overcome, a negative experience to be avoided, a deficiency in need of remedy. Building on the theory of deep learning in science ...as a generative and sensemaking process, the purpose of this design‐based study is to identify tactics for teachers to manage their students' epistemic uncertainty as a pedagogical resource to develop student conceptual understanding during whole‐class discussion. Classroom observations of whole‐class discussion were collected from six teachers' classes ranging from third to eighth grade. A total of 18 whole‐class discussions were collected, transcribed, and analyzed. A storyline talk to manage uncertainty during whole‐class discussion was developed and consisted of three stages: (1) Raise epistemic uncertainty through creating ambiguous conditions; (2) Maintain epistemic uncertainty through preventing immature disclosure and discussing alternative explanations or conflicting ideas; and (3) Reduce epistemic uncertainty through making coherent connections among current uncertainty, prior knowledge, and familiar phenomena. Seven nuanced tactics used by teachers to achieve each stage of uncertainty management were identified. The results suggest that managing uncertainty goes beyond asking questions and problematizing phenomena. When engaging students in storyline‐based whole‐class discussion, teachers should focus on one specific uncertainty and establish a coherent, consistent storyline that raises, maintains, and reduces student uncertainty to horizontally and vertically construct a collective knowledge among students. The horizontal nature occurs within a stage of management, and the vertical nature of a storyline talk is related to moving along from stage to stage. Through the storyline talk focusing on students' epistemic uncertainty, students can truly become agents in the learning process when the lesson is centered on and driven by students' uncertainty.
The novel coronavirus disease 2019 (COVID-19) infection has rapidly grown worldwide,
and many governments have implemented policies to control the infection rate. For example, school suspension, ...self-quarantine, requirement of citizens to stay at home,
travel and border controls, and discouragement of outdoor activities
have been used. Although these actions emphasizing the importance of "spatial distancing" are based on the perspective of public health, they may result in health problems other than COVID-19 infection, such as psychological distress and fear.
Therefore, the present authors examined the potential predictors for psychological distress among schoolchildren during COVID-19 school suspension.
•The generation of MSW is related to various features of urbanization.•The MSW composition was found to be closely related to the household population.•The volume of food waste generated was also ...related to the industrialization indicator.•MSW disposal fees should reflect not only household population but also tap water penetration.
The generation of municipal solid waste (MSW) is related to various features of urbanization. In this study, a linear regression model was used to evaluate the effects of several urbanization indicators on the composition of MSW. Household population (P), area of urban planning (L), tap water penetration (W), electricity sold (El), number of operating factories (I), car density (T), education level (Ed), and annual revenue (R) were chosen as important indicators of urbanization. The five major categories of MSW—paper, food waste, plastic, metal, and glass—were also chosen for specific analysis, and MSW composition was found to be closely related to household population (P) (r2 > 0.8). The volume of one category of waste, food waste, was related to the industrialization indicator (r2 > 0.9). The total volume of MSW and the total volume of metal waste were linked with household population divided by tap water penetration (P/W) (r2 = 0.9903), and with annual revenue divided by tap water penetration (R/W) (r2 = 0.9364). The volume of plastic waste and glass waste generated, respectively, was related to annual revenue divided by education level (R/Ed) (r2 = 0.9814 vs. r2 = 0.9371). In addition, a case study of Taipei City indicated that MSW disposal fees should reflect not only household population (P) but also tap water penetration (W). This study provides valuable findings quantifying the effects of urbanization on MSW composition. The results will help governments and enterprises to efficiently evaluate and predict variation in MSW composition with reference to indicators of urbanization, thereby improving the management of waste.
Abstract
Background
Owing to the heterogeneity of microbiota among individuals and populations, only
Fusobacterium nucleatum
and
Bacteroides fragilis
have been reported to be enriched in colorectal ...cancer (CRC) in multiple studies. Thus, the discovery of additional bacteria contributing to CRC development in various populations can be expected. We aimed to identify bacteria associated with the progression of colorectal adenoma to carcinoma and determine the contribution of these bacteria to malignant transformation in patients of Han Chinese origin.
Methods
Microbiota composition was determined through 16S rRNA V3–V4 amplicon sequencing of autologous adenocarcinomas, adenomatous polyps, and non-neoplastic colon tissue samples (referred to as “tri-part samples”) in patients with CRC. Enriched taxa in adenocarcinoma tissues were identified through pairwise comparison. The abundance of candidate bacteria was quantified through genomic quantitative polymerase chain reaction (qPCR) in tissue samples from 116 patients. Associations of candidate bacteria with clinicopathological features and genomic and genetic alterations were evaluated through odds ratio tests. Additionally, the effects of candidate bacteria on CRC cell proliferation, migration, and invasion were evaluated through the co-culture of CRC cells with bacterial cells or with conditioned media from bacteria.
Results
Prevotella intermedia
was overrepresented in adenocarcinomas compared with paired adenomatous polyps. Furthermore, co-abundance of
P. intermedia
and
F. nucleatum
was observed in tumor tissues. More notably, the coexistence of these two bacteria in adenocarcinomas was associated with lymph node involvement and distant metastasis. These two bacteria also exerted additive effects on the enhancement of the migration and invasion abilities of CRC cells. Finally, conditioned media from
P. intermedia
promoted the migration and invasion of CRC cells.
Conclusion
This report is the first to demonstrate that
P. intermedia
is enriched in colorectal adenocarcinoma tissues and enhances the migration and invasion abilities of CRC cells. Moreover,
P. intermedia
and
F. nucleatum
exert additive effects on the malignant transformation of colorectal adenomas into carcinomas. These findings can be used to identify patients at a high risk of malignant transformation of colorectal adenomas or metastasis of CRC, and they can accordingly be provided optimal clinical management.
Motivated by “company+farmer” farming operations of Wens, New Hope Liuhe, and Huiren, this study formalizes the impact of production‐management and resource‐providing types of contract farming, in ...which the buying firm commits to an ex ante procurement price and promises to buy the high‐value agricultural product (HVA) from contract farmers. We analyze the buyer's cost reduction effort and its impact on farmer participation to characterize the effect of contract farming on the agricultural product supply and all stakeholders. Additionally, we explore the impact of the HVA's production cost. We analytically show that all contract and non‐contract farmers are better off after an introduction of contract farming for HVA. Hence, contract farming can improve the farmers’ income and alleviate poverty. However, if HVA is costly to produce, there will be an inequality‐widening type of contract farming in which contract farmers are more efficient than non‐contract farmers, and the income disparity among farmers will widen. Otherwise, there will be an inequality‐reducing type in which contract farmers are less efficient than non‐contract farmers such that the income disparity among farmers will decrease. More importantly, the buyer benefits from a lower HVA's production cost, but this can hurt all contract and non‐contract farmers for a given equilibrium type. Moreover, reducing the HVA's production cost can increase the supply of a substitutable traditional product along with the switch of equilibrium from the inequality‐widening type to the inequality‐reducing one.
Atomically thin boron nitride (BN) is an important 2D nanomaterial, with many properties distinct from graphene. In this feature article, these unique properties and associated applications, often ...not feasible with graphene, are outlined. The article starts with characterization and identification of atomically thin BN. It is followed by demonstrating their strong oxidation resistance at high temperatures and applications in protecting metals from oxidation and corrosion. As flat insulators, BN nanosheets are ideal dielectric substrates for surface enhanced Raman spectroscopy (SERS) and electronic devices based on 2D heterostructures. The light emission of BN nanosheets in the deep ultraviolet (DUV) and ultraviolet (UV) regions is also included for its scientific and technological importance. The last part is dedicated to synthesis, characterization, and optical properties of BN nanoribbons, a special form of nanosheets.
Boron nitride (BN) nanosheets have many properties distinct from graphene, and therefore enable applications not available to the carbon counterpart. In this Feature Article, the unique properties and novel applications of BN nanosheets are summarized.
Chiral benzylic amines are privileged motifs in pharmacologically active molecules. Intramolecular enantioselective radical C(sp3)−H functionalization by hydrogen‐atom transfer has emerged as a ...straightforward, powerful tool for the synthesis of chiral amines, but methods for intermolecular enantioselective C(sp3)−H amination remain elusive. Herein, we report a cationic copper catalytic system for intermolecular enantioselective benzylic C(sp3)−H amination with peroxide as an oxidant. This mild, straightforward method can be used to transform an array of feedstock alkylarenes and amides into chiral amines with high enantioselectivities, and it has good functional group tolerance and broad substrate scope. More importantly, it can be used to synthesize bioactive molecules, including chiral drugs. Preliminary mechanistic studies indicate that the amination reaction involves benzylic radicals generated by hydrogen‐atom transfer.
A highly enantioselective intermolecular benzylic C(sp3)−H bond amination by using a chiral cationic copper catalyst and oxidant di‐tert‐butyl peroxide is reported. This mild, straightforward method can be used to transform an array of feedstock alkylarenes and amides into chiral amines with high enantioselectivities, and it has good functional group tolerance and a broad substrate scope.
A feasible approach is reported to reduce the switching current and increase the nonlinearity in a complementary metal–oxide–semiconductor (CMOS)‐compatible Ti/SiNx/p+‐Si memristor by simply reducing ...the cell size down to sub‐100 nm. Even though the switching voltages gradually increase with decreasing device size, the reset current is reduced because of the reduced current overshoot effect. The scaled devices (sub‐100 nm) exhibit gradual reset switching driven by the electric field, whereas that of the large devices (≥1 µm) is driven by Joule heating. For the scaled cell (60 nm), the current levels are tunable by adjusting the reset stop voltage for multilevel cells. It is revealed that the nonlinearity in the low‐resistance state is attributed to Fowler–Nordheim tunneling dominating in the high‐voltage regime (≥1 V) for the scaled cells. The experimental findings demonstrate that the scaled metal–nitride–silicon memristor device paves the way to realize CMOS‐compatible high‐density crosspoint array applications.
The scaling effects on the resistive switching behaviors and conduction mechanism in complementary metal–oxide–semiconductor‐compatible Ti/SiNx/p+‐Si resistive‐switching random‐access memory memristor devices with different sizes are investigated. Low power gradual reset switching and enhanced nonlinear characteristics in the scaling cells with sub‐100 nm size provide considerable potential for high‐density crosspoint memory array applications.
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